The present facts indicate that enzymes necessary for penetration of the ovum are located in the sperm acrosome. Therefore, the objectives of this study are to evaluate the present methods for the removal of acrosomes and acrosomal enzymes and develop a standard sequential method for removal of acrosomal components. Further, purify, characterize and determine the physiological role of acrosomal enzymes and investigate the natural and synthetic inhibitors of enzymes. The ultimate aim is to evaluate these findings as to their possible use in contraceptive technology. The acrosomal enzymes will be extracted using dilute MgCl2 extraction to remove the plasma and the outer acrosomal membranes followed by the NaCl and detergent extraction of the equatorial segment and the inner acrosomal membrane. The enzymes will be purified by ion-exchange, gel filtration, affinity chromatographic techniques and by isoelectric focusing. The effect on ova will be determined by incubating pure enzymes singly or in combination with intact ova or partially denuded ova. The presence of the inhibitors of acrosomal enzymes in the seminal plasma will also be investigated. The specificities of the inhibitors will be determined both biochemically and by their effect on fertilization both in in vitro and in vivo systems.